=?iso-8859-2?Q?Egy=FCd_Csaba?= <csegyud@vnet.hu> writes:
> E.g. I have four dates (D1, D2, D3, D4) and I want to know if (D1,D2)
> intersects (D3,D4) or not.
See the OVERLAPS operator:
( start1, end1 ) OVERLAPS ( start2, end2 )
http://developer.postgresql.org/docs/postgres/functions-datetime.html
regards, tom lane